It is common knowledge that young children, i.e. children of the age from where they can sit upright alone (app. 6-7 months) until they overcome sitting safely in a children's chair without falling out (app. 2 years), need harnesses that keeps them from falling out of children's chairs.
Conventional harnesses are often employed, of such type which comes with a pram, children's chair or which can be bought separately. In children's chairs, the harnesses are often anchored by straps on both sides of the seat in fitted fastening device, such as eyelets or the like.
In the last few years, there has been a development towards more countries and regions having their own safety requirements for equipment to be used for children, such as children's chairs and harnesses. This is taken into account when developing new children's chairs, but it can be difficult to adjust chairs that have been produced over a long period of time, prior to such safety demands came into force. It is particularly difficult to carry out such adaptations on chairs that have already been sold for several years and there are thousands of children's chairs existing in individual homes.
This is the case with the children's chair Tripp Trapp®, developed as early as 1972 and patented in 1976, and which still is a very popular children's chair in many countries. The chair is designed to be adjusted in accordance with the body size of the child and thus has a seat plate and a foot rest which can be moved into various height positions by sliding into grooves in the side members and are locked by tightening the distance between the side members. The seat plate can be further adjusted in depth position in that the plate may slide in relation to the back rest, and thereby providing the child using the chair the correct seat length under its thighs.
Thus, it has proven difficult to adapt existing seats to new requirements, particularly e.g. requirements wherein the anchor for the children's harness should follow the height position of the seat by a certain distance, such as for example 75 mm between the mentioned parts, and/or for example being kept constant in depth relation to the back rest.
Further, it has been an object to provide a fastening device as extra equipment so that also owners of older chairs may upgrade their chairs. It has also been an object to avoid physical operations such as making holes in any of the parts or inserting screws which leave spoiling marks in the chair that will show when the children's harness is no longer needed.